This invention relates to the production of mail pieces in a variety of configurations. More particularly, it relates to a sheet feeder for an apparatus and process which produces mail pieces in a selected one of a plurality of possible configurations.
Self-mailers are mail pieces which are produced from pre-cut forms which are folded and sealed to form a mail piece, and are well known, as is apparatus for printing and forming such self-mailers. Commonly assigned, co-pending U.S. application Ser. No. 407,583, to: Samuel W. Martin, filed Sep. 14, 1989 (C-574) discloses one such self-mailer wherein a pre-cut form is printed on a laser printer, or similar computer output printer, and fed to a folding and sealing apparatus to produce a self-mailer. Similarly, U.S. Pat. No. 3,995,808 to: Kehoe, issued Sep. 7, 1976 discloses another self-mailer wherein a web of forms is printed, folded longitudinally and sealed, and separated to form individual self-mailers. U.S. Pat. No. 4,063,398 to: Huffman, issued: Dec. 20, 1977 discloses another self-mailer wherein a web of forms is folded transversely to produce self-mailers. Huffman also provides for insertion of preprinted piece or "stuffers".
In general self-mailers as taught by the prior art are useful as a means of generating large numbers of mail pieces, but are limited in that they can be formed into only a small number of configurations. (By configurations, as applied to mail pieces herein, is meant variations such as use of a windowed or a printed envelope, variations in the number and type of printed pages, and variations in the number and type of pre-printed inserts.) At most, like Huffman they may provide for an ability to insert "stuffers". Further, with the exception of the above mentioned U.S. application Ser. No. 407,583 the equipment for producing such self-mailers has generally been physically large and suitable only for use in environments such as large computing centers.
Where it has been necessary to provide greater flexibility in the configuration of a mail piece which may be produced the solutions taught by the prior art have generally involved the use of inserters. An inserter is a transport system having a plurality of stations and along which a "control document" is transported from station to station. At selected stations pre-printed inserts may be accumulated with the control document and at the last station the entire accumulation is inserted in a pre-formed envelope. A typical use of such inserter systems would be by a bank mailing monthly statements to its customers, where the control document would be individual statements printed on the bank mainframe computer and the inserts would include each individual's cancelled checks. Such inserter systems are described, for example, in U.S. Pat. No. 3,935,429; to: Branecky et al. for: Process and Apparatus for Controlling Document Feeding Machines; From Indicia Contained on a Document Fed Therefrom; issued: Jan. 27, 1976.
Inserters do provide a high degree of flexibility in producing mail pieces in a number of configurations, and have proven very satisfactory for users such as banks and credit card companies. However, they suffer also from major limitations. First, because inserter systems generally do not operate under the control of the computer which prints the control document, a very significant problem exists in assuring that the proper inserts are matched with the correct control document. Because of this difficulty it has generally been necessary to use window envelopes with inserter systems rather than printed envelopes, so that an address pre-printed on the control document could be used to deliver the mail piece. Finally, inserters, like equipment for producing self-mailers, are generally quite physically large and suitable for use only in a large computer operation or production mail room.
Another approach to the problem of producing mail pieces was developed by Pitney Bowes Inc., assignee of the subject invention, under contract with the U.S.P.S. This equipment, known as PPHE (for Printing and Paper Handling Equipment) printed a continuous web, collated and separated the web to form sheets, folded the collated sheets longitudinally, and wrapped an envelope form around the wrapped sheets. The PPHE had a capability to add "stuffers" to a mail piece and was intended for production applications only, as the equipment was tens of feet long. The PPHE lacked capability to print envelope forms or handle variable length sheets.
A particular problem which arises in apparatus for the production of mail piece, and particularly where such apparatus is intended for an office environment, is the need to provide reliable sheet feeding for a variety of diverse paper sizes and weights. This problem is increased in apparatus which is intended to handle pre-printed sheets, where the pre-printed sheets may be printed on any of several different types of stock.
Thus it is an object of the subject invention to provide a sheet feeder mechanism which is capable of handling diverse sizes and weights of sheets.
It is another object of the subject invention to provide such a sheet feeder mechanism which occupies a small volume and is suitable for use with apparatus intended for the office environment.